Various multi-purpose tools have been proposed which combine several functions, such as that of a level, square and protractor. Such tools generally comprise two pivotally connected arms with protractor-like, angle measuring indicia near the pivot point, or elbow, to read the angle between the arms, and a bubble level on one of the arms for leveling purposes.
A disadvantage of such prior art tools is that they can not be relied upon for making precise angle measurement between two adjoining surfaces or for tasks which require cuts at precise angles, such as mitering corners for picture frames or floor moldings, for example, and for non-traditional cuts such as 45 and 90 degrees. The available space for angle markings at the elbows of such tools is severely confined, and so the angle gradations are often limited to increments of 5 degrees or more. These tiny scales are also difficult to read, and so the decree of accuracy of such scales is low. As a result, mitered corners are either undercut or overcut, resulting in undesireable gaps and poor fits.
Another disadvantage of the prior art tools is that the elbows are not structured to enter an inside comer between two adjoining surfaces as close as possible, and so the actual measured angle is spaced further from the corner than may be desired. Such measured angle may not be the true angle at the inside corner, particularly where the adjoining surfaces are slightly warped or have other surface imperfections.
A further disadvantage is that the prior art tools combine fewer functions or tasks than desired by tradespersons, and so other tools or instruments must be used or carried to perform the omitted functions, such as that of a measuring tape.
What is therefore desired is a novel multi-purpose measuring tool which overcomes the limitations and disadvantages of the existing tools. Preferably, it should provide for a precise reading of angles between adjoining surfaces of up to 0.5 degrees. The angle readings should be easily visible to a user in relatively large numerals for enhanced reliability. In particular, the tool should employ a dual-purpose flexible measuring tape to make traditional measurements of distance, and for use in a novel manner to provide the above-noted angle readings. The tool should have an elbow design which permits close entry into inside corners for more precise measurement of inside angles. The tool should be of a compact design to facilitate handling and use, and should combine multiple functions, including measuring inclines, corner angles and distances, and be capable of use as a square, bevel gauge and torpedo level.